European Expert Opinion on Infrarenal Sealing Zone Definition and Management in Endovascular Aortic Repair Patients: A Delphi Consensus

Abstract

Purpose: The purpose of the study was to provide a consensus definition of the infrarenal sealing zone and develop an algorithm to determine when and if adjunctive procedure(s) or reintervention should be considered in managing patients undergoing endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA).

Methods: A European Advisory Board (AB), made up of 11 vascular surgeons with expertise in EVAR for AAA, was assembled to share their opinion regarding the definition of preoperative and postoperative infrarenal sealing zone. Information on their current clinical practice and level of agreement on proposed reintervention paths was used to develop an algorithm. The process included 2 virtual meetings and 2 rounds of online surveys completed by the AB (Delphi method). Consensus was defined as reached when ≥ 8 of 11 (73%) respondents agreed or were neutral.

Results: The AB reached complete consensus on definitions and measurement of the pre-EVAR target anticipated sealing zone (TASZ) and the post-EVAR real achieved sealing zone (RASZ), namely, the shortest length between the proximal and distal reference points as defined by the AB, in case of patients with challenging anatomies. Also, agreement was achieved on a list of 4 anatomic parameters and 3 prosthesis-/procedure-related parameters, considered to have the most significant impact on preoperative and postoperative sealing zones. Furthermore, the agreement was reached that in the presence of visible neck-related complications, both adjunctive procedure(s) and reintervention should be contemplated (100% consensus). In addition, adjunctive procedure(s) or reintervention can be considered in the following cases (% consensus): insufficient sealing zone on completion imaging (91%) or on the first postoperative computed tomography (CT) scan (91%), suboptimal sealing zone on completion imaging (73%) or postoperative CT scan (82%), and negative evolution of the actual sealing zone over time (91%), even in the absence of visible complications.

Conclusions: AB members agreed on definitions of the pre- and post-EVAR infrarenal sealing zone, as well as factors of influence. Furthermore, a clinical decision algorithm was proposed to determine the timing and necessity of adjunctive procedure(s) and reinterventions.

Keywords: AAA; Delphi consensus; EVAR; sealing zone.

Figure 1.

Schematic overview of (A) the pre-EVAR target anticipated sealing zone (TASZ) and (B) the post-EVAR real achieved sealing zone (RASZ) in the infrarenal aorta. The TASZ is the length starting just inferior to the distal renal artery and ending at the most proximal slice at which the endograft is anticipated to no longer be in circumferential apposition to the aortic wall (also considering the endograft oversizing). The distal point of reference (blue area) is influenced by the degree of oversizing. The RASZ is the length starting at the proximal end of the endograft fabric and ending where the endograft material is no longer circumferentially apposed to the aortic wall. The TASZ and RASZ should be measured over the centerline between the reference points, or in case of patients with challenging anatomies, as the shortest length between the reference points.

Figure 2.

Survey results on parameters influencing the preoperative target anticipated sealing zone (A) and the postoperative real achieved sealing zone (B). Conf: configuration (conical vs non-conical), TT, thrombus thickness; TC, thrombus circumference; CT, calcification thickness; CC, calcification circumference; IFU, instructions for use; AUI, aortouniiliac.

Figure 3.

Algorithm developed by the Advisory Board. AAA, abdominal aortic aneurysm; CT, computed tomography.